A growler is a large, reusable container-commonly made of glass, ceramic, or stainless steel-used to transport draft beer. It is typically filled directly from the tap at breweries or brewpubs and sealed with a twist-cap or similar closure to keep the beer fresh, usually for about ten days

. Growlers usually come in sizes of 64 ounces (half a gallon) or sometimes 32 ounces (called a howler or half-growler), making them a convenient way to take craft beer home or on the go

. They are popular among craft beer enthusiasts for being both economical and eco-friendly, as they are refillable and help maintain the beer’s carbonation and flavor

. The term "growler" dates back to the late 1800s and is believed to have originated from the grumbling or growling sound made by the CO2 escaping from early beer pails as they were carried home

. Today, growlers are widely used and often customized with brewery logos or other designs, and they come in various styles including insulated versions for better temperature control

. In summary, a growler is a reusable jug designed for carrying draft beer from breweries, valued for its practicality, freshness preservation, and cultural history within the craft beer community.